Add chicken stock, crushed tomatoes, diced tomatoes, sugar, salt, pepper, Italian seasoning, and onion powder to the pot. (If you want smoother soup, put the diced tomatoes in a blender to break down their size before adding to the pot)
Allow the soup to simmer for 10 minutes, stirring occasionally.
Finely chop 15 basil leaves and add to the soup.
From the jar of sun dried tomatoes in oil, add about 1 tbsp of the oil to the soup. Finely dice 1/4 cup of the sun dried tomatoes and add them to the soup.
Add 1 cup of whipping cream and simmer for 10 minutes.
While the soup is simmering, cut your cheeses for the sandwiches. Butter one side of the sourdough bread and place it on the griddle. Layer on the medium cheddar and white cheddar cheese and cover with another piece of bread buttered on the outside. Once the sandwich is golden brown, flip it over until golden brown.
Serve immediately with a cup of the tomato basil soup. Enjoy!